1. Field of the Invention
The present invention relates generally to a handoff method for a mobile terminal and, more particularly, to a method and apparatus for performing handoff between Wi-Fi and 3rd Generation (3G) mobile networks, without interrupting ongoing communication.
2. Description of the Related Art
Voice Call Continuity (VCC) provides seamless call services between Wi-Fi and 3G mobile networks. When using VCC technology to provide a seamless call service, the signal strength of a Wi-Fi network is measured during a call and, when the signal strength is weak, call connection is reconfigured using a 3G mobile network. Therefore, it is important to identify a handoff occurrence time in VCC technology.
To identify a handoff occurrence time, a mobile terminal may estimate the probability of a handoff occurrence by periodically measuring network signal power. However, this estimation usually involves a large margin of error due to discrepancies between the measurement cycle and user movement between networks.
In addition, repeated measurements of network signal power increases power consumption in the mobile terminal, where power saving operation is critical.
Additionally, fast user movement between networks often makes it difficult to accurately identify a handoff occurrence time.